In now -- Now, from the recent scares at the embassy to the recent scares in the skies. Airplanes may still be the safest way to travel. Consider this stunning fact. July is not over yet but it's already the fifth deadliest month in aviation history. That has lawmaker calling for changes, even putting missile defense systems on airliners. ABC's David Kerley has the latest. Heads down, hands up! Heads down, hands up! Reporter: The latest aviation incident captured on cell phone video on Friday. A heavily armed Canadian S.W.A.T. Team storming a plane. All sparked by a passenger's bomb threat. Another air scare after a week of tragedy. From Ukraine to Taiwan to Mali, it all has the flying pick on edge. Prompting this headline. One week, 462 lost in crashes. It's left many asking, is it safe to fly today? We have a long way to go before we have any sort of a trend. And yet, I understand why people get scared. But, the reality is, it's incredibly safe. Reporter: But a world in turmoil has created new havoc for the aviation industry. Rocket fire shutting down tel aviv's airport. For U.S. Carriers for two days this week. That prompted new calls to equip U.S. Planes with missile defense systems. As some of Israel's el Al airliners already carry. There are thousands of shoulder-fired missiles in the hands of terrorists from around the world. But no commercial plane in the United States fleet is defended. That's just wrong. Reporter: Scores of those missiles, called man pads, were looted from Libya in 2011, after the fall of moammar Gadhafi. Many of them untraced. They don't have to hit the plane. Just the firing of it against a plane will ground U.S. Civil aviation to a halt. Reporter: These weapons only pose a threat near takeoff and landing. To planes at low altitude. Unlike the missile that struck mh-17 at 33,000 feet. Over Ukraine. And the defense systems come at a steep cost. $1 million per plane. In 2008, American airlines tested one system at the request of homeland security. It was not put into wide use. The FAA said this week it is not considering requiring such systems. It makes no sense for the world's fleet. Because the remedy is very simple. You keep commercial airliners out of threat areas. You don't need the missile systems. Reporter: The threat areas are spreading. Airlines instructed to steer clear of the world's hot spots. Is that enough in a world that seems to be growing more dangerous? For "This week," David Kerley, ABC news, Washington. Here now, former white house security and transportation security adviser Fran Townsend and our aviation expert Steve ganyard. Let me ask you, are we doing enough when it comes to air safety? I think so. This has been a terrible July. In terms of the whole year up until now, it's one of the best years ever on record. You would have to fly once a day, every day, for 4 million years to be killed in a plane crash. That said there are things we can look at. One of them, what happened in Ukraine. General Breedlove, the nato commander, on the 30th of June, said we're seeing Russians train rebels on surface to air missiles, not man pads. That should have gone to aviation everywhere. Who is doing the risk assessment? There are better ways. Fran, it's very important to point out. Even if that mh-17 had a missile defense system, that works against the shoulder-fire missiles. Not the kind that brought that plane down. That's right. And it goes back to the idea of sharing intelligence. Very specific intelligence about the threat. If we understood that this sort of system was being transferred from the Russians to the rebels, you understand, the height at which you have to fly to avoid a system and avoid the area altogether should have been more widely known. One thing that was incredible about the flight over Mali, we still don't have a way to track a missing plane, even after what we saw with the first missing Malaysian airliner. If that plane went down over water, would we know where it is now? No. This is another thing I think we need to address that's come out recently. Mh-370 is still missing. We didn't know where the Algerian flight was for hours. In this day and age, we should not lose airplanes. We have to get nations together and the aviation community together to agree on what is protocol. There are very inexpensive fixes. Nothing has been done since we lost mh-370. Talk about the man pad threat. The headline is frightening. You see all these man pads, hundreds of them go missing in Libya. You have this image of terrorists out taking target practice. Are you worried about that threat? We have seen terrorist groups use man pads successfully. It happened against a civilian airliner. It's been awhile. It's been awhile. It happened in Africa. And you do worry about it. I mean, I will tell you, having just spent a lot of time on airplanes flying back and forth across Africa, it's where I worry about it the most. The Libyan stockpiles have gone missing. And it's a very serious threat. But again, it comes back to, as opposed to deploying these systems on airplanes as $1 million a plane, the answer is, if you have the intelligence and the protocols for sharing it appropriately, you can better understand the threat and avoid it. Adds opposed to spending all this money on anti-man pad systems. Let me ask you both. You pay attention to this as much as anybody. You're knowledgeable on this. When that airport was shut down in tel aviv. Not shut down. When American airlines were told not to fly into the airport, you thought that was the wrong move. A bad move to stop flying there? I did. When you understand the threat and you understand all of the screening that goes along with it, you look at the perimeter security around the airport and the intelligence environment there, the -- and by the way, obviously the FAA thought it was a bad move because they withdrew that guidance 36 hours later. It was ridiculous. It sends a bad signal when you're talking about the bad guys. They think they have control over the environment and they have to scared. I did think it was a bad decision. We kept the airport open in Baghdad. We did. If Baghdad can stay open with rockets landing every two minutes, we should be able to keep tel aviv. Everything is intelligence. Mitigating risks. I think it was a little bit too much, too far. Not well thought out. In terms of the overall threat, you heard the words from general Flynn. The head of the intelligence defense agency. He thinks we're less safe now than we were just a couple of years ago. I think that's right. This threat is diverse. It's metastasized. You have seen the bombmaker in Yemen. The big concern is the sharing of that information. His training of others like those in Isis, where you have foreign fighters. Now, you talk about 700 western passports. Maybe as many as 100 with American passports and battle-hardened, coming back to western Europe and the united States. We ought to be concerned. It's frightening. But it's very important before we go to point out, two of the crashes we saw this past week were weather-related. You bet. Are we more worried about bad weather on a plane or a terrorist with a missile? Weather is still far more dangerous than terrorists are. It's a safe place. Thank you very much. Colonel ganyard, Fran Townsend. Coming up, the plan to stop

This transcript has been automatically generated and may not be 100% accurate.

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